74521109418721 has 27 divisors (see below), whose sum is σ = 86849445840339. Its totient is φ = 63756366279648.

The previous prime is 74521109418719. The next prime is 74521109418727. The reversal of 74521109418721 is 12781490112547.

The square root of 74521109418721 is 8632561.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 69059839550625 + 5461269868096 = 8310225^2 + 2336936^2 .

It is not a de Polignac number, because 74521109418721 - 2¹ = 74521109418719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (74521109418727) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 51786732720 + ... + 51786734158.

Almost surely, 2^{74521109418721} is an apocalyptic number.

74521109418721 is the 8632561-st square number.

74521109418721 is the 4316281-st centered octagonal number.

It is an amenable number.

74521109418721 is a deficient number, since it is larger than the sum of its proper divisors (12328336421618).

74521109418721 is an frugal number, since it uses more digits than its factorization.

74521109418721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4606 (or 2303 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 52.

The spelling of 74521109418721 in words is "seventy-four trillion, five hundred twenty-one billion, one hundred nine million, four hundred eighteen thousand, seven hundred twenty-one".